In Linnaeus‘ time Two Kingdom classification (Kingdom Plantae & Kingdom Animalia) was developed.
Drawbacks of 2-kingdom classification
Prokaryotes (Bacteria, cyanobacteria) and eukaryotes (fungi, mosses, ferns, gymnosperms and angiosperms) were included under ‘Plants’. It is based on the presence of cell wall.
But prokaryotes and eukaryotes are widely differed in other characteristics. It included the unicellular and the multicellular organisms in same group. E.g. Chlamydomonasand Spirogyra were placed under algae.
It did not differentiate between the heterotrophicfungi and the autotrophicgreenplants.
Fungi have chitinous cell wall while the green plants have cellulosic cell wall.
